To arrive at the relative value of various foods, it is absolutely necessary to carefully estimate their different nutritive qualities.

By this table it will be seen that some expensive foods are really even more costly than they appear at first sight, because of the small proportion of flesh-forming, or nutritive quality they contain. As an instance of this one shilling will buy only 7 ozs. of salmon, containing 2 per cent nitrogen., while the same sum will buy 30 ozs. of shin of beef, containing 3 per cent, nitrogen, or 24 ozs. of cheese, containing 4 per cent.

The heat-giving qualities can be estimated by comparing the large percentage of carbon which such foods as oatmeal and potatoes contain with the small amount which is found in various meats. Thus one shilling will buy 136 ozs. of hominy, containing 40.28 per cent, of carbon, or 192 ozs. of potatoes, containing 81 per cent., whilst it will only buy 13 ozs. of steak, which contains 11 per cent, of carbon.